Detection of four DNA genetic marker systems to differentiate individuals in mixed seminal stain of two individuals / 中国法医学杂志

Objective To investigate personal identification of mixed seminal stain of two individuals, we combined the detection of genotyping autosomal, Y and X STR and sequencing mtDNA hypervariable Ⅰ (HV Ⅰ ) region. Methods We analyzed autosomal, Y and X STR with commercial kit and separating and sequencing HVⅠfragments of mixed seminal stain from two males by SSCP electrophoresis. Results Four genetic markers of the high amount sample can be obtained when mixed ratio is more than 1:10. When the proportion of two samples is close, the suspect could be excluded or, to some extent, identified by comparing with our results. Conclusion The combined detection of four genetic marker systems can, to some degree, solve the personal identification from mixed seminal stain of two individuals.

Study on SNP Genotyping of Degraded DNA by Fluorescence-labeled Multiplex LDR-PCR Amplification / 中国医科大学学报

Objective In this study,a multiplex PCR amplification system was constructed based on fluorescent labeling PCR and LDR,to provide a new strategy for analyzing severely degraded DNA.Methods Eight SNP loci (rs10802248,rs10516197,rs10488372,rs2278945,rs4757318,rs4887255,rs4889002,and rs9304473) were selected.Their LDR probes and PCR primers of linked products were designed and synthesized.Ligase detection reaction,PCR amplification,and capillary gel electrophoresis (CEG) were performed to establish the multiplex LDR-PCR amplification system.Results The genotypes of these 8 loci were obtained simultaneously by the fluorescence-labeled multiplex LDR-PCR amplification method.The loci profiles obtained by fluorescence-labeled multiplex LDR-PCR amplification were in accordance with those obtained by direct sequencing of the polymorphic regions in samples from all individuals.By fluorescence-labeled multiplex LDR-PCR amplification,the 8 SNP loci were efficiently amplified from the severely degraded FFPET DNA.Conclusion Eight SNP loci results could be obtained simultaneously by using the multiplex LDR-PCR amplification system,which is a simple,efficient,and practical SNP genotyping method with accurate and reliable results for highly degraded samples.